The present invention relates generally to the art of document processing equipment such as scanners, printers, facsimile machines and combination devices which use single sheet feeders to pick single sheets of media to be processed from a stack thereof. Such equipment includes sheet moving rollers, belts or wheels and, in particular, the sheet feeders with which the present invention is concerned employ both a pre-feed roller and a separation roller spaced downstream from the pre-feed roller. A stack stop is positioned to be moved into and out of the path of sheet movement between the rollers. Worn or otherwise damaged rollers in such equipment occasionally require replacement necessitating a service call and attendant expense. It is accordingly desirable to provide a modular single sheet feeder which can be easily assembled at the factory and which also has easily replaceable rollers which can be serviced by the user without the necessity to involve a skilled service technician.